


Damnation: The One Where Sherlock Shags the Fuck Out of Mycroft, and We’re All Happily Going to Hell

by phipiohsum475



Category: Sherlock (TV)
Genre: Alpha!Sherlock, Alpha/Beta/Omega Dynamics, Bonding, Knotting, M/M, Marking, Omega!Mycroft, Oral Sex, PWP, Rimming, Scenting, Sibling Incest, Teenlock, Underage - Freeform, heat - Freeform
Language: English
Status: Completed
Published: 2015-07-17
Updated: 2015-08-01
Packaged: 2018-04-09 19:21:32
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 7
Words: 10,387
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/4361231
Author URL: https://archiveofourown.org/users/phipiohsum475/pseuds/phipiohsum475
Summary: <blockquote class="userstuff">
              <p>“What is that scent?!” Sherlock demanded angrily, and Mycroft shrugged, prepared for the slightly obtrusive methods of his younger brother in his own search for answers. Sherlock turned on him, with a growl, and came up to Mycroft from behind, hands on his shoulders to keep Mycroft from standing. Sherlock buried his nose in Mycroft’s neck and moaned, “Fuck, it’s you! It’s bloody obscene, you smelling like that. How do they allow you out in public?!”</p><p> </p><p>  <b>Sherlock is 15, Mycroft is 22</b></p>
            </blockquote>





	1. Presentation: Or Alpha Sherlock Presents Early, Because of Course He Does

**Author's Note:**

> Thanks to [Janto321](http://archiveofourown.org/users/FaceofMer/) and [HumsHappily](http://archiveofourown.org/users/HumsHappily) for the beta.

It took Mycroft Holmes less than a day to realize his little brother was to do something he never had. There was no doubt that Sherlock Holmes, at the tender age of fifteen, was presenting. The adolescent fell into deep sleeps for upwards of sixteen hours a day, and spent the remaining eight ravenously hungry and, true to form, complaining about how presenting was wreaking havoc on his studies.

If Mycroft didn’t find jealously a completely useless sentiment for oneself to have (provoking it in others had its advantages, of course, but all the more reason to rise above such petty feelings himself), he might have felt envious of Sherlock’s transformation. The month long sleep and eat binge was a necessity in creating the muscular strength attributed to all alphas, to build a thick, appealing physique, with the dense tissue capable of almost inhuman strength during situations of increased adrenaline. But with the physical alpha attributes came the hormonal ones, which Mycroft was all too willing to avoid.

Having not presented by his 19 th birthday, Mycroft was content to be a beta. He was neither overly muscular, nor adorned with soft, sloping curves. According to those so designated, he was missing out on a world of spectacular sex and deep, instinctive bonds, but Mycroft was quite pleased with the sex he did have. His preference for male betas meant he wouldn’t have children, but given his plans of world domination through subtle puppeteering, that was clearly for the best.

No, though he watched his baby brother shift from chubby pre-pubescent to an impressive specimen of lean alpha strength, Mycroft was pleased to be a beta.

-o-

“And how’s our dearest Sherlock?” his mother asked, and Mycroft sighed. He knew his mother’s daily calls were not to inquire about his health and well-being during Mummy and Father’s month-long line dance competition in the States, but to inquire about Sherlock. Likely, Mycroft assumed, Mummy felt guilt over the timing of the competition, just two weeks into Sherlock’s presentation. Though there was no way to know in advance that Sherlock would present so early, though alphas  _ could _ present anytime between fifteen and eighteen, near ninety percent presented at seventeen. And omegas presented almost exclusively between sixteen and eighteen; but leave it to Sherlock to be ahead of his peers.

Mycroft knew that with Sherlock sleeping most of the day anyways, he could finish the last of his doctorate thesis relatively undisturbed, so he had offered to watch the little imp to assuage Mummy’s concern. Yet, trying to be sensitive and considerate, she asked a plethora of questions of Mycroft before conceding to the true purpose behind her call. Mycroft tried to reassure her that he’d feel equally cared for if she just called to check in on Sherlock; that he didn’t need a half hour discussion on his life and another quarter hour on her own, but she would hear none of it.

So, Mycroft sighed, ready for the call to end. “Sleeping loads, as always. Charles has six to eight ready to heat meals in the refrigerator at any given time, so regardless of when he wakes up, he’s got food ready to go within five minutes. He’s fine, Mummy. I promise you I will call if anything changes. You don’t have to check in every day.”

“Oh, hush, of course I do! Now, within the next week or so, he should start sleeping less, and at once, his scenting will develop. He may be a bit overbearing at that point, you know how he must teach himself just everything. And scenting, well-“ his alpha mother began to explain, and Mycroft cut her off. He didn’t need the reminder of what he was missing.

“-Yes, like seeing the world in black and white, then waking up with colours,” Mycroft parroted blandly, the same description of scent he’d heard from everyone with a designation.

Mummy chuckled, “Yes, of course you’ve heard it all, haven’t you dear? Well, just be patient with him!”

“Yes, Mummy”

“We love you, Myckie, and Sherlock too!”

“Love you, too.”

-o-

Mycroft finished his thesis first draft and sent it to his advisor for review two days later. It was his third doctorate and he felt confident his work would only need the barest of revisions. He rather thought the degree was just for show; he was more than competent in all the work he wished to do, but somehow the acquisition of a degree was considered proof of competency rather than competency itself. Thus, Mycroft planned to collect a handful in a variety of fields, leaving him perfectly suited to claim authority over any department he saw fit as he ascended to the shadows in his career.

Sherlock was sleeping less than before, weaning down to ten to twelve hours, but still far more than the six he preferred. He’d burst into the kitchen, fit to eat a horse, and devour what he could, before stalking down Mycroft and complaining. Once the growing alpha fulfilled his “requisite drama,” as Mycroft measured in ultimatums and asinine declarations, Sherlock would disappear to his room for experimentation, reading, research, and much to Sherlock’s dismay, more sleep.


	2. Realisation: In Which The Brothers Discover Mycroft is Not the Beta They Thought He Was

Mycroft sat in his room the evening after his submission in his finest silk pyjamas, the smooth fabric helping ease his mild discomfort. He treated the remaining anxiety with an exquisite brandy and a book of Persian poetry he’d set aside as a treat after his thesis was done. He’d found a fan to blow a cool breeze over him; the warmth of the brandy causing a blush to rise over his skin. There was an itch on his nerves, something leaving him unsettled. He heard the bold, arrogant stomping of his little brother, and all slotted into place. Mycroft rolled his eyes, mentally marked his location, and was thusly prepared when his bedroom door burst open, slamming it into the stopper on the wall and bouncing back onto his newly defined form.

“What is that scent?!” he demanded angrily, and Mycroft shrugged, prepared for the slightly obtrusive methods of his younger brother in his own search for answers. Sherlock turned on him, with a growl, and came up to Mycroft from behind, hands on his shoulders to keep Mycroft from standing. Sherlock buried his nose in Mycroft’s neck and moaned, “Fuck, it’s you! It’s bloody obscene, you smelling like that. How do they allow you out in public?!”

Mycroft tried to stand, to push back against Sherlock he sat in the chair, but Sherlock licked a wide stripe up Mycroft’s neck with his warm, wet tongue. Mycroft stuttered, the heat and moisture sending static down his spine and through his nerves. Sherlock took his moment of weakness to press his tongue deep into Mycroft’s neck, seeking for something Mycroft knew he wouldn’t find. And yet, he knew the moment that Sherlock’s tongue felt the deeply buried gland. Mycroft gasped and Sherlock chuckled.  Mycroft tried once again to stand, to escape, to flee from the slowly dawning realisation, but Sherlock, and his newfound strength, refused to allow it.

Mycroft slapped both hands down on the desk in front of him, as Sherlock dragged his front teeth over the gland he’d sought and successfully found. The alpha pulled back, “You- you’re an omega. I  _ knew _ it. You couldn’t have smelled so delectable otherwise.”

“I’m a-“ Mycroft focussed hard to spit out, “-A beta. You know this. Beta.”

“No,” Sherlock growled. “Omega.  _ My _ omega.”

“Sher-“ Mycroft began to protest, but Sherlock spun the chair around, pulled Mycroft from his seat, and backed him into his own bed. “Sherlock! This is- You can’t-“ Mycroft tried to stop him, but even he could tell that his own words were weak and superfluous. Sherlock would take what he wanted, and Mycroft would ultimately give it to him, as he always did.

Sherlock pulled the silk pyjama shirt over Mycroft’s head, then flipped him onto his belly. Mycroft stopped trying to get up, stopped trying to move, the itch he’d been feeling growing stronger and more insistent. Sherlock loomed over him, scenting him further, slowly thrusting against Mycroft’s backside. He nibbled again on Mycroft’s neck and growled with pleasure as Mycroft whined beneath him.

Sherlock pulled his silk pyjama trousers down with a fumbled effort, his focus still on the scent and taste of Mycroft’s neck, on his glands, and spurred further by Mycroft’s muffled moans and gasps.

“Delicious,” Sherlock muttered, running a hand over Mycroft’s flank and down the slope of his arse.

Mycroft tried, one last time, to object, “I’m not an omega!”

Sherlock thrust two fingers, without preamble, into Mycroft’s arse. Mycroft waited for the pain to erupt, but instead he felt the rapturous slide of Sherlock’s fingers slide deeply in and out of his hole, his way paved with slick. Mycroft groaned, and Sherlock grinned, all teeth, as he switched sides and scraped against the gland that had begun to bulge on the left side of his neck. Never mind that Mycroft’s groan was less for the pleasure and more for the confirmation that Sherlock was right: he was an omega. A late presenting, hidden, deceitful omega, and Sherlock, his  _ baby - bloody-fucking-brother-Sherlock _ , was his alpha.

Mycroft whimpered, and suddenly, the hot flush of his skin and the feverish itch that wouldn’t go away all made sense. Sherlock pulled away from his neck, and pressed apart his firm arse, exposing Mycroft with a beautiful vulnerability. The alpha dipped down and licked a stripe from Mycroft’s bollocks to the top of his arse, and the most undignified noises escaped the both of them.

Sherlock continued on, his thick tongue spreading him open, delving inside him, craving all the sweet slick Mycroft had to offer. As Sherlock indulged in his scent, Mycroft felt pulse after pulse of slick release, drenching his arse, his  cloaca , and Mycroft pulled himself onto his knees, pressing his arse deeper into Sherlock’s ministrations. The itch he’d been feeling gave way to hollowness, and he found himself begging, without his permission,  “More. Deeper, Sherlock, harder. I need more!”

Sherlock nuzzled his face into Mycroft’s arse, then quickly leapt up to nip at the glands now swelling in Mycroft’s neck. Mycroft, for his part, was so enraptured in the sensations of his glands being manipulated that he nearly missed that Sherlock had hastily thrust his own slacks down.

Sherlock let his cock fall into the cleft of Mycroft’s arse, enjoying the slide provided by the copious amount of slick Mycroft was releasing, and muttered wickedly into his ear, “What was it you needed?”

Mycroft groaned, trying to arch his back and entice Sherlock to properly satisfy him, but Sherlock twisted with him.

“Say it,” Sherlock demanded, biting softly on one of his glands. He shuddered and gasped beneath Sherlock, and he knew instinctively that the more hormones Sherlock could coax into his bloodstream, the more wet and compliant he would become.

“Just fuck me, you insolent brat!” Mycroft attempted to sound cross, but instead sounded desperate and debauched.

Sherlock moaned agreeably. “Good, so good, my delicious omega,” he praised, and as a reward, slowly began to breach Mycroft’s aching, writhing body. Mycroft let out a low, deep whine as Sherlock pushed further, further, and further still. He was regretting not having seen Sherlock’s cock before begging for it, but the burn that accompanied the stretch was glorious and satisfying on a primal level. Once he’d filled Mycroft, Sherlock gasped, panting hotly into his neck, “It’s-uhn- _ oh _ !”

A puff of laughter escaped Mycroft, who wanted to taunt Sherlock about being rendered speechless, but found he had difficulty putting the words together himself. So instead, he rolled his hips back into Sherlock, a silent reprimand for breaking their tentative agreement; Mycroft would ask, and Sherlock would deliver.

Sherlock growled at the suggestion he was failing in his responsibility. He sat up on his knees, scraping his teeth along Mycroft’s shoulder blades as he did so. He pulled out, and with two firm hands, gripped Mycroft’s hips tightly, painfully. For a moment, he paused, daring Mycroft to say a word, then thrust in snarling and sheathed himself in just one swift movement.

“Oh! That!” Mycroft breathed, “Perfect!”

Mycroft could hear Sherlock’s smugness in the hitch of his breath, but was rather pleased that Sherlock was, for once, doing exactly as Mycroft wanted. Sherlock handled him roughly, and Mycroft offered no resistance, letting his baby brother fuck into him with abandon. And as he was in everything, Sherlock was both spectacularly selfish, yet amazingly brilliant. Though he sought his own release, his ego as an alpha was also at stake, and Sherlock used every ounce of his bulky musculature to please them both. Mycroft was indulging himself, his nerves sparkling hot, firing pleasure into every cell of his body as Sherlock manhandled him. He could barely think, his brain fogged with nothing but lust and arousal, seeking to maximize the benefits of both.

Sherlock’s breath began to stutter, and he fell forward, placing one hand on Mycroft’s neck to hold him down and wrapped the other around his belly. Mycroft had only a moment to wonder why, until he felt Sherlock press against his belly and gasp as the alpha felt the thick shaft of his cock pass under his hand. Sherlock pushed down harder on his neck, using it as leverage to fuck him harder, faster, and each time he felt his own cock swell under Mycroft’s abdomen.

The feeling pushed Sherlock to the edge, and Mycroft felt his knot begin to inflate, each pump of Sherlock’s hips sending it past his already tender rim, and he felt the widening pressure inside him. Sherlock seemed unaware of his thickening girth, never ceasing in his relentless pace and Mycroft’s ability to keep silent finally evaded him. “Jesus, Sherlock, don’t stop, please, just, just knot me already, please, Sherlock,” he begged.

And as a final resort, Mycroft gasped, “Please, my alpha, please.”

Sherlock damn near wailed at Mycroft’s submissive request, and shoved into him one last time, the fat bulge knotting sinfully against Mycroft’s prostate, and he could feel each throb of Sherlock’s cock as it emptied into him, warmth flooding his system. His own orgasm followed soon after, a torrent of ecstasy coursing through him, and he cried out, wanton and coquettish. As the pleasure ebbed, he pulled softly against the knot, knowing it wouldn’t release him for some time, but milking each pulse of Sherlock’s cock, feeling his own spent cock twitch with delight, though it remained woefully untouched.

Sherlock, throbbing through a fourth and fifth orgasm, gave soft gasping moans each time, a delightful sound Mycroft found comparable to most of the classic composers. Spent, Sherlock fell to Mycroft’s left, knotted tightly, and draped an arm around his elder brother. His words came back to him slowly.

“Bloody brilliant. Is.. is it always that  _ spectacular _ ?”

“Certainly not with betas,” Mycroft scoffed, realising now just how unparalleled the sex truly was, “I’ve not been with an alpha before though.”

Sherlock growled, “You won’t. No one but me. You’re mine.”

Mycroft ignored him, “Just rest for bit Sherlock. From what I understand, we may be expending quite a bit of energy over the next few days.”


	3. Possession: Bath time, Blowjobs and Sherlock Stakes His Claim

Mycroft lay, strangely comfortable despite Sherlock’s knot still locking them together. His little brother had his arm draped over him, hand on his belly, nose nuzzled into Mycroft’s neck, and slept peacefully, with soft snores. Mycroft’s pheromones grew stronger, as he descended further into his heat. The haze of arousal clouded his thoughts, and all that mattered was the alpha behind him, who held him close. He dozed on and off for a half hour or so, until he felt Sherlock’s knot soften and slip from inside him. Mycroft rolled off the bed, careful not to disrupt Sherlock, who still needed his sleep, and he padded off to his en suite. He was sticky with slick and come, and turned on the shower. He kept the water cool to offset the feverishness that was returning, and stood under the spray until he felt relief. He lathered the soap into his hands, and as he ran it over his body, the scent became overwhelming, clogging the air, causing him to retch. He quickly rinsed off his body, but the overwhelming scent remained, and he scrubbed at his skin, trying to neutralise the odour.

The door burst open, and Sherlock pulled open the shower. “What did you _do_?” he scowled.

Mycroft kept scrubbing, senses still besieged, “I don’t know! There’s something wrong with the soap!”

Sherlock yanked Mycroft out and crowded him against the wall, snarling, “Why did you wash at all? Were you trying to rid yourself of my scent? Am I not good enough for you?”

As Sherlock pressed bodily against him, the odour of his terrible soap paled in the overpowering allure of _alpha_. Mycroft’s eyes grew wide and he stuttered, “You. Alpha. _Oh_.” He buried his face into Sherlock’s neck, taking in breath after deep breath of the heady pheromones. Sherlock smelt of the air before a rainstorm more than anything, but the scent was mixed with an arousing bouquet of sex and passion and want and Mycroft felt slick drip down his thighs as he rubbed against Sherlock, trying to mark himself with the invigorating fragrance of _his_ alpha.

Sherlock chuckled huskily, “I’m going to have to mark you properly this time.” He wrapped one hand around Mycroft’s neck and the other slipped down to his arse, where Sherlock dipped his fingers into the wetness of Mycroft’s dripping hole. Sherlock fingered him shallowly, letting his hand become properly drenched in Mycroft’s slick. He dragged Mycroft in by the neck and whispered in his ear, “On your knees.” He nipped Mycroft’s gland as he pulled away, and Mycroft buckled under the command.

Sherlock slicked up his cock, and Mycroft found himself eye to eye with the alpha’s engorged arousal. He subconsciously licked his lips, watching Sherlock stoke himself, unable to get his large hand completely around his girth. He was twice as long as Mycroft, and Mycroft watched, mesmerised as Sherlock pumped his cock, occasionally licking his hand to both provide more wetness, and to spurn himself on with Mycroft’s taste. With his other hand, he pressed two fingers against Mycroft’s mouth, “Open.”

Mycroft complied, unable to imagine not doing whatever Sherlock asked of him. Sherlock slipped the fingers into his mouth, and Mycroft wrapped his lips around the digits, sucking and licking as he kept eye contact with his little brother.

Sherlock groaned. “Good. So good for me,” he smiled with open lust and affection.

Mycroft felt deep satisfaction at the praise, and moaned around Sherlock’s fingers. Sherlock pressed against his tongue, and he recognized the silent request, opening his mouth wide.

Sherlock placed the tip of his cock against Mycroft’s tongue, continuing to stroke himself while Mycroft licked generously at the head. Mycroft wrapped his lips around Sherlock’s cock, taking in just a bit, as much as he could handle without gagging, and brought his hand up to feel Sherlock’s swollen bollocks, bulging with the plentiful come that Mycroft knew his own pheromones were inducing.

“Mycroft, fuck,” Sherlock gasped, and pulled out of his mouth, hand flying rapidly over his erection.

Mycroft closed his eyes, aware of what was coming. He felt the first stripes of Sherlock’s come over his face, in his mouth, and then Sherlock aimed lower, coating his shoulders and chest. When he no longer felt the warm ribbons of ejaculate adding to the mess, he opened his eyes, seeing Sherlock leaning over him, one arm against the wall, holding him up. He watched until Sherlock opened his eyes and sought out his own. Sherlock pushed off the wall, and stepped back, taking in the full sight of his elder brother, come dripping down his face, covering the freckles on his shoulders, and striped over the fine ginger curls on his chest.

Sherlock’s eyes were wide and lustful, despite having just come. “You are bloody gorgeous,” he breathed and held out a hand to help Mycroft up. Mycroft went to grab a towel from the rack, but Sherlock stopped him with a firm “No!” Instead the alpha dragged him back to the bed, where he delicately laid Mycroft on his back. He straddled Mycroft’s hips, and then softly, like a tender massage, rubbed his come into Mycroft’s skin. He dipped his fingers in it like finger paint, then slowly kneaded Mycroft’s chest, his belly, his arms, then slid further down, marking Mycroft until the last of his ejaculate was dried onto Mycroft’s flesh.

Mycroft’s senses were all on high alert, but nothing more noticeable than his sense of smell. Having Sherlock spread his seed over him, to know by scent just how claimed he was, was intense, as though he could imagine the moment of being born, submerged in a brand new world, and nothing would ever be the same again. His cock jutted upwards, rock hard, and he knew that his slick was practically gushing over the sheets beneath him. His consciousness briefly noted that had circumstances been different, he would have been disgusted by his body’s betrayal of sentiment and lust, not to mention the mess of fluids surrounding him, but Sherlock’s possessive scent dragged him back to the most primal of desires.

Sherlock laid next to him, then rolled him over so that Mycroft was perched on top of him. Instantly, Mycroft’s hand went to his own neglected cock, but Sherlock batted it away.

“Come here,” he instructed, gesturing upwards, and Mycroft shuffled up until he reached Sherlock’s neck. “I want to taste you,” the alpha said, desire laden dark in his eyes.

Mycroft sat up on his knees, leaning against the headboard, and lowered himself until his cock pressed against Sherlock’s lips. He looked down at his younger brother, who in the midst of their changing relationship, no longer seemed like the petulant child Mycroft considered him to be even a few months prior. His body had changed, and now he just saw a strong, fit, strapping man beneath him; his alpha, his lover, his soul.

Sherlock opened his mouth in invitation. Mycroft slid himself into the wet heat, gasping as Sherlock swallowed the whole of his smaller cock. Sherlock placed his hands on the swell of Mycroft’s arse, pushing him deeper, and Mycroft began to fuck Sherlock’s mouth in earnest. He panted hard, holding onto the headboard for leverage, knowing that he’d need something more soon.

“Sherlock, I need you- God- your cock, please,” he begged. Instead a thrill flashed in Sherlock’s eyes, and suddenly deft fingers plunged into his arse. Mycroft moaned and found himself thrusting between Sherlock’s mouth and the fingers teasing his prostate. He rolled his hips, but it still wasn’t going to be enough, not with the ache of heat burning deep inside him. “Sherlock, I need more, please!”

Sherlock held tight onto his hip with his other hand, digging his fingers into the flesh, refusing to let Mycroft shift down towards his cock. Instead, he slipped a third, then fourth finger into Mycroft’s loosened, drenched hole, and Mycroft gasped at the sudden fullness. He pumped his hips hard, fucking deep into Sherlock’s throat and back onto the thick spread of Sherlock’s fingers. He held onto the headboard with both hands, vigorously chasing his orgasm.

“Fuck, so- so fucking close- Christ, Sherlock, just a little bit more,” Mycroft pleaded, having no idea what it was he needed more of, but trusting that Sherlock would provide.

Sherlock, knowing exactly what his omega was seeking, tucked his thumb into his palm, and as Mycroft thrust back down into his fingers, allowed the whole of his hand to slide past the tight rim, then made an immediate fist to simulate his knot. Mycroft howled loud and ecstatic as he came, filling Sherlock’s mouth with his bitter seed. Sherlock swallowed enthusiastically, desperate for his omega’s taste, and Mycroft pulsed time and time again until spent. He pulled out of Sherlock’s mouth, slumping over him, panting from the delicious overexertion.

Sherlock grinned, hungrily wiping his mouth, “You are utterly delicious.”  

Mycroft blushed, but slid down until he lay next to Sherlock, breathing deeply, catching his breath. “I think,” he huffed, “That we need some sort of food.”

Sherlock took stock of his transport, and looked back to Mycroft, “That is an excellent idea.”


	4. Adoration: In Which Mycroft Refuses to Sully Mummy’s Kitchen Chairs, but Sherlock Wants Him Anyways

Mycroft knew better this time than to wash any part of Sherlock’s affections from his body, and instead, tossed on a silk dressing gown. The itch of his skin had ebbed, though he suspected it would be back if he waited too long to be bedded yet again by his alpha.

Sherlock, for his part, strode about the house unabashedly naked. Mycroft told him to lay down a flannel before sitting on the chairs in the kitchen’s breakfast nook, and opened the refrigerator to find which of the meals would be best. Something quick, heavy in proteins and carbohydrates. He found a meaty lasagne, and at Sherlock’s approval, popped the meal into the microwave per the instructions Charles had scrawled on the aluminium. Mycroft poured himself a large glass of milk, and Sherlock an ice water. They gulped the drinks in silence, only now realising how desperate their bodies were for sustenance.  

The lasagne was rich and satisfying, but then again, Charles never disappointed. Once they’d both had their fill, Sherlock eating more than Mycroft had ever seen in a sitting, and Mycroft allowing himself seconds  _ just this once _ _,_ Mycroft cleared the table. He filled the sink with hot water, letting the dish soap bubbled up to soak the dishes. He was operating on autopilot, the disdain of dirty dishes echoing deep from his childhood. As he waited, Sherlock came up behind him.

“You are mine,” Sherlock declared, nuzzling his neck, “You know that, right?”

Mycroft smiled, tilting his head to allow Sherlock better access, “Yes, Sherlock, I know.”

“It’s not normal, is it?” Sherlock asked, before sucking a soft bruise into his flesh.

Mycroft moaned, but focussed long enough to answer, “When have either of us ever been normal?”

Sherlock nibbled on his earlobe, and spoke with a hot whisper in his ear, “I didn’t think I’d ever find an omega. No one would want me. But you were just a room away. Perfect, brilliant, gorgeous. And all for me.”

Mycroft sighed, content. “All for me,” he echoed the sentiment.

Sherlock wrapped his arms around Mycroft’s waist, then undid the belt of his dressing gown. He pulled the fabric off Mycroft’s shoulders, and let his hands drift over his omega’s naked form. Mycroft held his hands down on the counter’s edge. Sherlock pressed kisses down his spine, pulling him away, so that Mycroft was stretched far from the edge he held onto. Pleased at how he was bent, Sherlock fell to his knees behind Mycroft, spreading him open wide. He dove his tongue into Mycroft without preamble, and Mycroft nearly buckled from the onslaught. Sherlock was thorough, taking care to taste every curve and crease. He murmured noises of approval when Mycroft felt himself slicken, wet and warm. Mycroft felt the empty, hollow, craving  return, and knew that his body was begging for his alpha to sate him once again.

“Need you,” Mycroft gasped out.

Sherlock bit the swell of his arse softly, then prompted, “What do you need?”

Mycroft felt the flush on his face, mortified at the very idea of asking for something so intimate so directly, but the burning need inside him ached, and thus he moaned, “I need your cock, Sherlock. I need to be fucked, filled,  _ claimed _ by my alpha.”

Sherlock bit his other arse cheek, then with a grin so wolfish, Mycroft could hear it, said, “You have no idea how much I love to hear you beg. My big brother, always giving the orders, craving me so badly he’ll beg me for it.” Sherlock lapped at his dripping hole one last time, before standing up. He slipped behind the omega, and let out a huff of annoyance as he realised that Mycroft was still too tall. “Not fair,” he muttered, and pulled Mycroft up, swivelling the two of them around. Sherlock stepped him backwards, attempting to push him down into the chair he’d been in earlier, but Mycroft caught the handrails of the seat and refused to buckle.

“No!” Mycroft protested, “I do not want to have to explain to Mummy why her kitchen chairs are soiled!”

Sherlock smirked. “Just as well,” he commented, right before sweeping Mycroft’s legs up around his waist, and plunging into him. Mycroft groaned with deep satisfaction, despite the awkward position of still holding himself up by his arms. He gripped the chair tightly as his brother fucked into him. Sherlock held him with two strong hands at the small of his back, pulling Mycroft’s body onto his cock with a brutal pace. Mycroft might have been the taller of the two, but it was clear his alpha was the stronger, and Mycroft couldn’t help but be mesmerised by the lean, powerful flex of Sherlock’s biceps as they tensed and heaved in time with his thrusts.

Sherlock panted, “At me, look at me,” and Mycroft sought out the gorgeous galaxies hidden in his brother’s eyes. He remembered briefly how jealous he’d been as a child of Sherlock’s gorgeous eyes and the attention they afforded him. He’d hated his dull, greyish blue ones in comparison.

But Sherlock looked at him with such devotion, such lust, and Mycroft could barely stand the sentiment that they betrayed. He tried to look away, but Sherlock protested.

“No, I want to see you,” Sherlock gasped breathlessly. “I want to see how you take me. The look in your eyes when you come. When I make your belly swell, pumping you full of my seed.”

Mycroft moaned, the image clear in his head. He unwrapped one leg, then the other from Sherlock’s waist, and instead draped them over his alpha’s elbows, spreading his legs. The change in angle made his brother’s cock fill him even more deeply, and he could already feel Sherlock’s knot begin to swell.

Sherlock huffed appreciatively, moving his hands from under Mycroft’s back around to hold onto his hips, now that his arms were holding most of the omega’s weight. He gripped harder and Mycroft felt his fingers dig into the same grooves from before. He knew he’d have bruises by his heat’s end. Without warning, Sherlock thrust the bulge of his knot past his rim. Mycroft howled in the pleasured pain of it all,  barely keeping his eyes locked with Sherlock’s. The dark lust of Sherlock’s gaze sparked Mycroft’s own climax, and, still desperately gripping the chair’s handrails beneath him, Mycroft’s eyes slammed shut as he came in short, sputtering ropes across his own abdomen. Sherlock’s cock throbbed, pulsing copious amount of ejaculate deep into him, and Mycroft could barely catch his breath as he saw the opened his eyes and saw the undisguised want in his brother’s eyes.

As Sherlock spent the last of his seed inside him, he placed his hands back under Mycroft for support, and shrugged off Mycroft’s legs from his shoulders. He hitched Mycroft up, holding him tightly to his own chest, smearing the mess of Mycroft’s come between them. He nuzzled his face into Mycroft’s neck and hummed happily as he carried Mycroft out of the kitchen, and into the sitting room. He carefully manoeuvred them to the leather sofa, which their mum had carefully guarded against staining years before. Sherlock settled them down, Mycroft still joined to him, and leaned back to look at his omega, freshly corrupted.

Mycroft watched Sherlock closely from his perch on the alpha’s lap, and found that the lust had given way to a deeper affection. He nibbled at his bottom lip and looked away, finding it hard to accept such affection, freely given. His relationship with Sherlock had been strained for years, ever since Sherlock had lost the hero worship of his big brother, and instead found Mycroft’s restrained demeanour and deferment to social conventions abhorrent.

He raised his head and gazed upon Sherlock, who was watching him with such adoration, pressing his hands against Mycroft’s soft middle to feel not only the hardened rod of his own cock, but the supple engorgement that his knot so determinedly kept in place. It was nearly impossible to keep looking. He tried to glance away again, but Sherlock caught the motion and, while keeping one hand on Mycroft’s prominent swell, raised the other to direct Mycroft’s stare back to him.

“No,” Sherlock whispered, like it was secret just between them, despite the emptiness of the house. “You will always be my overbearing older brother, and I, your impertinent, appalling brother. But don’t ever believe that I could imagine anyone, not a soul, more perfectly suited to me than you. No one. I’m never letting you go, you understand that? Mine, Mycroft, always mine.”

A warmth blossomed through Mycroft’s chest, and he found himself grateful for words he hadn’t known he needed to hear. He lacked the capacity to dwell on the logistics; bonds between siblings were extremely rare, and highly frowned upon, despite the fact that nature was more at fault than the participants themselves. To be so desolate and matchless such that only your own bloodline could possibly suit you, well, Mycroft cursed himself for not realising sooner that this thing between Sherlock and he was obviously inevitable.

But he could worry about that later, and instead, he flung his arms around Sherlock’s neck, burying his nose to scent his alpha. He felt boneless, relaxed, and, quite without his permission, he fell asleep in Sherlock’s embrace.


	5. Reciprocation: Or, Mycroft Tops From the Bottom Like A Boss

Mycroft awoke to the subtle roll of Sherlock’s hips. He could tell the alpha’s knot had waned, but he’d become feverish and uncomfortable in his sleep. Sherlock, clever as he was, clearly noticed, and had gently begun the task of pleasing his omega, even as he slept. With sleepy countenance, Mycroft’s awareness came to him as the tide to the beach. As the waves crashed to the shore, his eyes grew wide with desire, and he bore down on Sherlock’s cock, rock hard and buried deep inside him. He felt his own slick drip down, drenching Sherlock’s bollocks, his thighs, and as Mycroft began to ride Sherlock’s perfect prick, the obscene sound of slick flesh slapping together echoed off the vaulted ceilings.

Sherlock beamed at Mycroft’s sudden enthusiasm, and leaned back, placing his hands behind his head, to take in the full effect of watching his big brother bounce on his cock, mouth open and panting, that round little curl plastered to his forehead with sweat and exertion, eyes all consumed with a primal need to fill the aching emptiness of an omega in heat.

Sherlock took a deep breath, trying to contain himself, but couldn’t stop himself from uttering, “Gorgeous. Christ, My, you have no idea.”

Mycroft blushed, feeling less gorgeous, and more a reckless, shameless tart. Sherlock saw the doubt flash in his eyes, and slid one arm up Mycroft’s chest, and kept murmuring praise between gasped breaths, “So beautiful. My omega, so good. So tight, so hot. Dripping wet. Just for me. Perfect.”

Sherlock, from this position, was able to alternate between tugging softly at the short ginger curls adorning Mycroft’s chest, and rolling one nipple then the other between his fingers. Mycroft groaned, placing his hands on the sofa behind Sherlock, and with his newfound leverage, was able to pull nearly completely off Sherlock’s cock, only to slam the thick length of it back into himself. Sherlock shouted out as the pleasure was punched from his lungs, and Mycroft’s glassy eyes met his briefly. Mycroft grinned, a dangerous grin, Sherlock knew, and his eyes grew wide. Mycroft moved his hands from the sofa to Sherlock’s shoulders, and then, with a sudden, brutal, unrelenting pace, began to fuck himself on Sherlock’s cock, each stoke pulling nearly entirely off of his alpha, only to ram back down over and over again. Sherlock could hardly bare the onslaught, and both of his own hands gripped the back of the sofa as Mycroft took control, using Sherlock as little more than a toy, eyes closed, mouth in a perfect O, less seeking release than forcibly taking it from Sherlock.

Sherlock stuttered, struck speechless by the force of Mycroft’s will. Mycroft sought power and control in his goals for global manipulation, but Sherlock obviously failed to realize those traits could extend even to his own heat. He’d shown remarkable submission as he grew accustomed to the reality of his new omega identity, but now that he’d catalogued and learned, it was time to take back his command. He peeked at Sherlock through heavily lidded eyes. Mycroft took satisfaction in Sherlock’s shocked expression, and it spurned his arousal, his body producing even more slick, which only served to further ease the way for Sherlock’s significant girth. Just knowing he could still surprise Sherlock, even after all this time, brought him close to the edge, and one hand left Sherlock’s shoulder to reach for his cock.

Sherlock, shaken from his stupor by Mycroft’s self gratification, reached down to hold his brother’s hips, digging his fingers in the same places as before, consciously hoping to leave dark bruises for Mycroft to remember fondly. His knot grew, his body near bliss at Mycroft’s possession of him, and he couldn’t take his eyes off Mycroft’s face as the omega thrust downwards, clearly hungering to impale himself with the bulging knot as he frantically fucked upwards into his own fist.

As Mycroft shoved himself down onto the swell, his eyes flashed with anger as he glared at Sherlock. “Dammit, Sherlock, fucking knot me already!”

Sherlock’s knot obeyed immediately, filling out to its fullest girth, and Mycroft, with one last forceful motion, bore down, taking the whole of it. Sherlock blanked out, the ecstasy of his own submission pouring through his veins, and he released wave after wave of come into his commanding older brother. In turn, Mycroft exploded onto him, white ribbons decorating his chest, from his neck to his navel.

Mycroft recovered first, and he gave a knowing smirk with a mild taunt, “Such a  _ good _ alpha for me, Sherlock.”

Sherlock wanted to protest, but the extra burst of bliss that came with his next orgasm silenced him. It appeared he rather appreciated the praise Mycroft gave him. It’d been years since Mycroft had given him any such honour, although in fairness to his elder brother, it’d been years since he’d tried to impress him.

That clearly was going to change.

As Sherlock continued to empty himself into the silky, feverish heat of his omega’s cloaca, Mycroft began to smear his ejaculate over Sherlock’s chest, much like Sherlock had done to him. When Mycroft was satisfied that Sherlock was sufficiently claimed, he leaned into Sherlock to purr in his ear, “And now, you’re mine as well, Sherlock. I hope you’re prepared to handle me.”

Sherlock throbbed through one last orgasm, and tossed his head back, chest heaving.

Mycroft reclined back, perched haughtily on Sherlock’s cock, as if to claim his ownership. When Sherlock finally looked up, puffing deep breaths as though he’d run a marathon, Mycroft tilted his head and crooked a single brow. He still wasn’t done teaching Sherlock that any power Sherlock had in this relationship of theirs, was only the power that he allowed Sherlock.

He started to circle his hips, Sherlock’s knot pulling against him, sending tendrils of delicious ache rolling up his spine, and Mycroft sighed with deep satisfaction. Sherlock whimpered, and Mycroft snapped his head down.

“Oh, yes,” he smiled, then dipped down to his little brother, threading fingers up those dark curls. He’d adored them for years, their bounce, their chaos symbolic of Sherlock’s own. He hauled the alpha towards him, with the beautiful raven locks as leverage, and pressed his lips against Sherlock’s. His lips were dry and chapped, and Mycroft licked them damp, then nibbled them red and swollen, darkly imagining how gorgeous sanguine ruby lips against pale skin would flatter his little brother.

Sherlock gasped into his mouth, and Mycroft took the chance to dip in his tongue, just a bit, to brush against Sherlock’s own; a subtle reminder of how they were connected, completely and circular, from the warm heat of their mouths to the throbbing knot joining them together. Mycroft raked the fingers from his other hand down Sherlock’s chest, no doubt leaving crimson stripes, and then sought out the boy’s nipple.

Mycroft started carefully, a brush, then a flick. Sherlock arched upwards into his hand, into his mouth, and Mycroft glowed, and his attentions grew more relentless. He tightened his grip on Sherlock’s hair, pulling to expose his long, porcelain neck, then rolled the pebbled nub hard, pinching as he brought his teeth to Sherlock’s neck.

Sherlock bucked beneath him with a luscious cry, and Mycroft growled. He bit down, staking his ownership with brutal force, knowing Sherlock would sport beautiful blooms of red violet bruises that would take days to fade into lavender and teal, then gold and chartreuse, all stunning flowers reminding his young alpha that in no uncertain terms, Mycroft had claimed him, just as thoroughly as he’d been claimed by Sherlock.

Mycroft moved lower, leaving a myriad of bites, tweaking the sore nub, then switching hands to deliver the same ravishing treatment to the other side of Sherlock’s neck and chest. The alpha squirmed and writhed, arching into Mycroft’s hands, wordlessly begging for more with his deep euphoric rumblings. His cock filled out, stretching Mycroft abundantly with perfect pressure, as though he was nothing more than an extension of Mycroft’s body. Mycroft chuckled, playing Sherlock like his piano, each nip, pinch, suck, lick and tug enchanting a symphony of rapture from his little brother’s body. 

Soon, the boy was trembling beneath him, and Mycroft felt the pulse of Sherlock’s heart in his carotid artery, which beat against Mycroft’s lips. Sherlock may not have a gland to bite or from which to coax hormones, but nonetheless, Mycroft’s zealous diligence sent his heart aflame. It took nearly no time at all, and Sherlock cried out, as Mycroft wrung another series orgasms from his body. Mycroft felt the warmth of being engorged with Sherlock’s climax, the alpha’s cock quivering inside his cloaca, pulsing through just two or three orgasms instead of the typical six to eight. Sherlock whimpered as his body came far sooner than he was prepared.

Sherlock fell boneless against the couch, and Mycroft licked soft twirls over the burgeoning bruises. “My alpha,” he muttered, “Perfect, the way you please me, the way your cock permeates me, your come saturates me. We are utterly connected.” Mycroft made a sudden face, “It’s revolting. This is exactly what I warned you against. What I warned myself against.”

He slumped, forehead on Sherlock’s shoulder, “I’ll never be able to let you go. You are, simply put, an enormous liability.”

Sherlock laid his hands on Mycroft’s back, giving him soft strokes down his flank. He let Mycroft nuzzle into him, and reminded him with a soft laugh, “You forget. I always have been.”


	6. Affection: or The Brothers Give Into Oxytocin, Despite Their Reservations

When Mycroft woke up, Sherlock’s arms were still wrapped around him. His brother had slipped out of them as they slept, and Mycroft could feel the slick dripping out of him, and the heavy scent of sex filled the room. It occurred to Mycroft suddenly that today was Wednesday, and Charles was due back mid-morning to cook several days worth the meals for them and tidy the manor. He buried himself into Sherlock’s neck and nipped at the dark marks like watercolours painted over Sherlock’s skin. Sherlock woke, and Mycroft felt the alpha’s cock stir against his perineum.

“Charles will be here in just a few hours,” he murmured in Sherlock’s ear, “Bring me to your bedroom?”

Sherlock chuckled smugly, but shook his head, “Water. Food.”

Mycroft outright laughed as he climbed off Sherlock’s lap, “I’m not sure I’d ever see the day you’d insist on food before pleasure.”

“Dearest brother,” Sherlock feigned offense, “How little do you think of your alpha?” He stood, brushing off imaginary lapels. “How can I be service if I’ve no energy? Digestion is bad for brainwork, but this? I need all I can get to satisfy your insatiable urges.”

“ _ My  _ urges?!” Mycroft exclaimed, but he still swung his hips as he left the room, giving Sherlock a show. He’d been assured his arse was perfectly lovely, and he rather hoped Sherlock agreed.

“If you weren’t so damned delectable, this might have all been avoided,” Sherlock quipped, but there was no heat to his voice.

Mycroft led the way back to the kitchen, head beautifully fogged with hormones, pheromones and the feverish glow of heat that was beginning to bead at his hairline. Sherlock swaggered behind him, and together, they raided the pantry for a quick, sustaining meal. After food and after he forced Sherlock to down a litre of water, he handed the alpha a tea towel.

“Take care of the sofa, and I’ll meet you in your bed,” Mycroft persuaded, with long finger tips tracing the line of Sherlock’s hipbones.

Sherlock scowled, but scampered off, and Mycroft poured himself a second tall glass of water. Dehydration was the most common complication of heats and ruts, and he refused to ignore his body that completely. He lingered, enjoying the cool water, then splashing some onto his feverish flush. He walked down the hall, meeting Sherlock halfway. Sherlock’s cock was bobbing, thick and full, and he growled hungrily as Mycroft approached. It was clear the hormones in the other room were still strong enough to leave Sherlock with a desperate need for his omega.

He pounced, dragging Mycroft to the closest surface. He pushed his big brother through the door of the dining room, and pressed him against the table, back down and legs spread, open and inviting.

Mycroft felt the slick gush from his body as Sherlock pushed apart his thighs with a hungry look. “Sherlock- no, upstairs- not here,” Mycroft protested; the dining room table where their parents took their meals was not an ideal location. Ignoring him, Sherlock bent down to engulf his cock, the searing heat of his mouth sending Mycroft reeling, while Sherlock slipping two fingers into his dripping hole. Mycroft arched up with an ecstatic cry, but his brother was relentless. Within just a few short minutes, Mycroft was panting, pleading,  _ begging,  _ “Please, Sherlock, fuck me, please!”

Sherlock popped off his cock, then looked into Mycroft’s eyes as he brought his wet fingers to his own lips. He slowly lapped the slick off them, and Mycroft groaned at just how delicious his alpha looked, perfect pink lips, wrapped around his own fingers, sucking hard enough to hollow out his cheeks as he indulged in Mycroft’s taste.

Then, in a swift motion that punched the breath from Mycroft’s lungs, Sherlock lined up and plunged inside him. The boy fucked him hard with a fierce rhythm, and Mycroft held onto the table’s edges, holding himself against the onslaught. As Sherlock pistoned into him, his felt his climax rise, a tangle of nerves building in his belly, until he tripped over the edge, painting himself, neck to navel, with his own come in thin stripes.

Once Mycroft had come, Sherlock pulled out. His knot was barely swollen, and while it caught on the sensitive rim of Mycroft’s arse, it wasn’t nearly large enough to knot him. Mycroft whined, lamenting just how empty he felt without Sherlock’s knot buried deep inside of him. The corner of Sherlock’s mouth twitched with a smile, seeming ever so proud of the noises and desperation he could wring out of his omega.

Mycroft made to glare at him, but was caught unexpectedly when Sherlock dipped down, and began to lick up the mess Mycroft had made of himself. Each swipe of Sherlock’s broad tongue up his chest, each soft suckle and kiss, sent waves of pleasured bliss through his entire body, and he fell boneless underneath his alpha.

After he’d cleaned the last of Mycroft’s come off his chest, Sherlock stood up again. Mycroft looked up, hazy with endorphins, and could see the hesitation on his brother’s face.

Mycroft gave a small puff of amusement, “Brother mine, there is simply no further reason to be bashful. We’ve nothing to hide from each other, not anymore.” He gestured to his naked body, and the acts they’d just completed.

Sherlock looked churlish, and huffed, “That’s different. It’s hormones, sex, nothing more.”

“Ah,” Mycroft said, understanding, “You’re feeling sentimental.” He spoke carefully, with a neutral tone, “If you wish, you may blame that on the hormones, too.  Oxytocin is quite powerful.”

The younger boy scoffed, “That’s for omega’s contractions and lactation; what’s that to do with me?”

“Oh, Sherlock,” Mycroft sighed with pleasant exasperation, “Don’t be stupid. Oxytocin exists in all mammals, it’s uses range from yes, motherhood, but also to orgasm, trust and bonding. You really must stop deleting your biology lessons. I assure you, any sentiment you display when we are alone, I will attribute to the hormones and the hormones alone. I shan’t blame you. I trust I can expect the same consideration?”

“Yes,” Sherlock agreed. “Well then,” he started, took a deep breath, and rushed out, “It appears my alpha instincts would very much like to carry you up to my bed.”

A deep swell of affection rose in his chest and Mycroft begrudged, “Apparently, my omega instincts are inclined to let you.”

Sherlock came around the side of the table, pressing a kiss to Mycroft’s lips. Mycroft wrapped his arms around the alpha’s neck as Sherlock slipped his arms under his back and thighs. He lifted Mycroft off the table, and held him close to his chest.

Sherlock muttered under his breath, “I will be absolutely mortified about this when your heat is over.”

“Won’t we both?” Mycroft scoffed, but his voice was mild, “However, I must admit this position gives me lovely access to your neck.” Mycroft pressed his nose into the pale skin, inhaling deeply, then nipping softly at the bruises he’d left earlier.

A low growl echoed out of Sherlock’s throat, and he tilted his head to allow Mycroft better access as Sherlock ascended the stairs. At the top of the landing, just as Sherlock had laid Mycroft on his soft silk sheets, they heard the key in the door and Charles’ shuffled gait.

His gritty tenor travelled through the house, “Masters Holmes? I shall be in the kitchen if you need me!”

Mycroft’s eyes bolted open, and with a hushed whisper, ordered, “The table, Sherlock!” Sherlock dismissed Mycroft with a wave of his hand, but Mycroft narrowed his eyes, demanding and authoritative. Sherlock rolled his eyes, but still rushed out the door, his instincts impressing upon him the need to placate his omega. There was still a great deal of slick smeared over the table, and a flannel covered in come laying on top of it, and Mycroft was sure to be mortified of his role in their proclivities were they discovered. 

Sherlock stumbled down the stairs, then stood straight and unashamed as he passed the kitchen door and headed into the dining room.

Charles caught the movement, “Oh, good morning, Master- Oh!” He abruptly turned his head, and chided, “Master Holmes, do put some clothes on!”

Sherlock swapped the table clean with the wet tea towel, and called out as he passed the kitchen again, “Can’t be bothered with clothes, Charles. Too constricting. Best to forgo cleaning the rooms upstairs till I’ve finished presenting.”

He didn’t wait for Charles to respond before jogging up the stairs, but he heard the elderly man’s answer anyway, “Yes, that would be best. Good day, Master Holmes.”


	7. Subjugation, In Which Mycroft Discovers the Joys of Bondage and Bites

He walked into his bedroom, to find Mycroft splayed out, feet down on the sheets, fingers shoved as deeply inside his own arse as possible, the other hand pinching and rolling his nipple, and making soft, sweet gasps as he tried to fill the hollow ache that Sherlock had left.

Sherlock crawled over him, long and elegant, grabbing his wrists forcefully and holding them tight above this head. He scraped his teeth against the gland Mycroft’s neck, and snarled, “Don’t you fucking dare, you little tart, you belong to me. I will fuck you hard and raw and fill you so fucking full of my seed you’ll never feel empty again.” He placed his mouth over the entire gland, and bit softly in promise.

Mycroft cried out, loud and wanton, and Sherlock clasped a hand over his mouth, “We can’t have that.”

Sherlock jumped off the bed, and spun frantic, looking around the room. His eyes lit up when they found the curtain, and he took the quick few strides of the room and yanked the curtain nearly off its rod before he turned, the curtain rope in hand, and a feral grin on his face.

Mycroft looked, eyes wide, and warned, “Sherlock.”

But his brother was already at his side, flipping him onto his belly. Mycroft wanted to protest, but the pressure and bites on his gland had delivered a fresh wave of hormones through his body, and he found himself persuadable and easily manipulated.

Sherlock bent over him, his cock erect and bulging against his back, and Mycroft felt the rope press against his lips. He opened his mouth, hungry to please his alpha, and Sherlock slipped the thick corded rope in between his teeth. Mycroft tried to bite down, but his jaw was open far too wide. He moaned at gag, feeling the saliva leak down his chin, and felt vulnerable, open and ready to be taken. Sherlock tied the rope behind his head, and turned Mycroft’s head to see how perfect his brother looked gagged, and growled at the sight.

“Christ, Mycroft, you have no idea how delicious you look like this, at my mercy; I’d love to see you bound further, hands behind your back, as I hold you down, knot you again and again, you gorgeous thing.”

Mycroft whimpered, but nodded his head, eyes pleading.

“Oh,” Sherlock huffed, realising, “You want that, too.” He launched himself from the bed, pulled the other rope from the curtain, and turned back, to where Mycroft had pushed himself to kneeling and placed his arms behind his back, the cord in his mouth cutting across his cheeks, where Sherlock knew they’d leave spectacular marks. Sherlock took great pains to keep his breathing under control as he dragged the silken ropes across Mycroft’s chest, then around his biceps, binding his wrists in the process. Mycroft made a muffled noise, the question in his moans obvious. Sherlock tried to laugh, but it still came out breathy and wanting, “I’ve learned a bit of rope work and escapism, after a half arsed kidnapping last fall by the rugby team. You’ll be fine.”

To emphasise his point, Sherlock slipped two fingers under the ropes at Mycroft’s wrist, around his biceps near his brachial artery, then he circled around to Mycroft’s front, where the ropes cut across his chest, brushing over his nipples, and Sherlock licked his lips, eyes dark, and Mycroft could read the lust, the desperate want in his features. His inner omega, the one who’d preened under Sherlock’s affection, then laid himself vulnerable at his alpha’s fingertips, now found himself aching as he never had before. He needed Sherlock, to fill him, to control him, to dominate him, to claim him. Mycroft felt the slick dripping down the inside of his thighs, and in a single meaningful gesture, bared his neck to Sherlock, offering it up, offering himself up to be mated.

Sherlock darted forward at the sign, licking a stripe up Mycroft’s neck, causing the omega to groan around the gag. He clambered around Mycroft, then pushed him down onto his chest, hiked up his hips, and bent low to lick the slick up the inside of Mycroft’s thighs, nibbling bites up white, sensitive flesh. Mycroft writhed underneath him, trying to thrust upwards, desperate to filled. Sherlock let his tongue wander up behind his bollocks, and sought out the source of his delectable scent, plunging his tongue into the hot, sopping hole, trying to devour all of Mycroft, to take him in so completely that Mycroft merged with him, in every cell of his body, that his tempting taste would be digested, enter into his bloodstream and he and Mycroft would be combined, whole, one.

Mycroft was gasping and panting, spit leaking out from behind his gag, leaving wetness on the sheets, but he barely noticed. His jaw began to ache around the thick cord, and the rope rubbed against his nipples, held his arms down and bound his wrists, and he felt utterly and deliciously debauched. He was solely focused on Sherlock, on his little brother’s tongue, always so beautifully clever, so wonderfully sharp, and he needed to scream, cry out, beg Sherlock for more.

Sherlock, once content with how wet Mycroft had become, slid up on his knees, and pulled Mycroft to his knees up by the ropes in the centre of his back. Mycroft whimpered as his head bobbed, and Sherlock nestled up against him, then pressed the head of his cock against his hole, teasing. Mycroft growled, and in one quick motion, sank down, filling himself with Sherlock’s cock, deep and as hard as he could, but it was still not quite enough.

Sherlock shouted against his shoulder, mouth opened, teeth bared, at Mycroft’s assertiveness. He wrapped his arms around Mycroft, gripping the ropes stretched around his chest, and began to pull him down. Mycroft whined around the cord as Sherlock finally, finally, fit him, filled him, split him open wide, and each thrust of that throbbing, thick cock left Mycroft bereft of air, heaving and panting. He tilted his head to the side, asking again.

Sherlock grumbled in his ear, “Oh yes, my omega, I will. I can’t have you flaunting that delicious scent all about that office of yours. Can you imagine? The way those alphas would look at you?” Sherlock slammed hard against him, fisting the ropes hard enough for them to bite Mycroft’s pale skin, leaving beautiful red welts. “But no, you’re mine. And best that you are. You’ll fade into the background now, just like you want, a bonded omega, nothing for  _ them _ to notice.” Sherlock mouthed at Mycroft’s neck as he snarled, the gland swelling nicely in preparation, “The best possible designation for someone like you, isn’t it?”

Mycroft, through his aching jaw, his spit riddled lips, and the cords leaving thick wide marks embedded in his skin, sobbed his agreement. He couldn’t imagine anything more perfect, more rapturous than this. Mating with Sherlock, well, if the young alpha had managed to appeal to his logical side, even cock deep inside him with a growing knot, well, who else could be better?

That lovely thick knot slipped in and out the tight rim of his hole, and Sherlock’s arms were wrapped around him, holding him tight, teasing that lovely gland with his tongue and his teeth, and Mycroft was so on edge all he wanted was to touch himself, or for Sherlock to touch him. His cock bobbed obscenely as Sherlock pounded into him, and he let out a series of whines and whimpers, his throat vibrating with his vocal exclamations and Sherlock grinned against his throat.

“So close, Mycroft, so close and then you’re mine, I’ll knot you, claim you, make you bleed. You’ll be mine, full of me, swollen with me, and your body will absorb all of me, and I’ll be written in every strand of your DNA, fuck Mycroft, can you feel how thick my knot is?”

Mycroft nodded, head still exposing the long, sinewy lines of his neck, feeling saliva drip down his chin and down his throat as Sherlock growled in his ear.

“Your arse is so deliciously tight, each time I thrust into you, it quivers and craves me, Christ, Mycroft, I’m- oh fuck, I’m going to knot you, I’m going to mate you, I’m going to fill you, tell me yes, tell me you want me as much as I want you.”

Mycroft nodded again, with muffled exclamation, eager and ready.

Sherlock growled one last time, and Mycroft felt the vicious thrust of a full knot past his rim, locking him tight with his alpha, followed immediately by Sherlock’s teeth breaking the skin of his throat, bursting the gland, sending a hot flush of hormones through his body with unrelenting pleasure. Mycroft cried out, through the gag, biting down in an attempt to withstand the ecstasy, and he came, hard, ribbons of come bursting forth onto the sheets beneath him.

Sherlock released his neck, his cock throbbing through one orgasm after another, and lapping the blood laced with pheromones. Sherlock let his tongue drift over the wound, and Mycroft remembered dimly that the mechanics of mating meant that Sherlock was being mildly drugged by the omega hormones in his blood.

Sherlock moaned deeply, humming against Mycroft’s neck, and listed to the side. Mycroft followed, and together they laid side by side on Sherlock’s soft black silk sheets. Sherlock nuzzled against his omega as he came again, and slowly his hands drifted to the knots adorning Mycroft’s back.

Mycroft melted as the ropes were unwound, filled with Sherlock, marked and mated, and he felt a deep contentment. Sherlock softly, near involuntarily, massaged his arms, his wrists, his chest, anywhere he’d been bound, and they both were breathing so deeply that Mycroft might have mistaken them for sleeping, if he weren’t so obviously awake.

Mycroft, had never, not once in his 22 years, felt such a sense of rightness. Of belonging. Of home. He had no clue how they’d manage, how’d they’d hide their taboo relationship, but right now, encased in Sherlock’s arms, neck throbbing with Sherlock’s bite, and the hormonal bliss surfing his bloodstream, Mycroft couldn’t possibly more serene.

Slowly, but peacefully, they drifted into sleep together.

**Author's Note:**

> I'm on [Tumblr](http://phipiohsum475.tumblr.com).


End file.
